Organic clay (OC)/natural rubber (NR) nanocomposites (NRCNs) prepared by melt blending were studied for the effect of clay structure and content on strain-induced crystallization of stretch crystalline rubber. Microscopic phase structures of NRCNs were characterized by XRD and TEM. The results showed that the stress of NRCNs increased gradually with increasing strain at beginning and increased rapidly after strain reached to a critical strain point (ε0) which strain-induced crystallization was occurred in NR. As clay was loaded higher

the crystallization started at lower strain. Dispersed OC nanoparticles with high shape aspect ratio restricted movement of rubber molecules

and also rigid parallel clay lamella structure promoted orientation of flexible rubber molecules in stretching process.